A particularly advantageous mounting device for anchoring a machine element to a rotary shaft which does not cause components to wear or damage the shaft during installation, use, or removal is sold under the trademark TRANTORQUE, and is shown generally in U.S. Pat. No. 4,202, 644 (the disclosure of which is hereby incorporated by reference herein). This mounting device is particularly useful for critical timing and high torque applications. The TRANTORQUE.RTM. mounting device includes an inner element, an outer sleeve set of segmented elements (typically three), and a nut that cooperates with them to move them relative to each other. The inner and outer elements have matching, opposite wedge tapers so that when the nut is turned the device expands and contracts, clamping onto the shaft and to an inner bore of the machine element; or the nut can be rigidly connected to the machine element.
While the TRANTORQUE.RTM. device has a number of desirable features, in applications where it must be frequently assembled and disassembled to the shaft, it is easily unscrewed too far, and falls apart, the inner and outer elements being detached from each other, and the multiple segments of the outer element becoming disconnected. This requires substantial time in reassembly, and occasions the possibility that some of the segments will be misplaced, and therefore, is desirably avoided. According to the present invention, this problem is avoided while still having no adverse affect on the mounting device. The invention is utilizable with almost any type of machine element, such as a gear, cam, pulley, roller, or the like.
According to one aspect of the present invention a mounting device for mounting a machine element on a shaft is provided which comprises the following conventional TRANTORQUE.RTM. elements: An inner generally tubular element having a through extending internal bore, and two distinct external portions, an externally screw threaded first portion, and a tapered wedge second portion, and at least one axially extending slot. An outer generally tubular element formed by a plurality of segments, the segments when assembled together defining a through extending internal bore having a tapered wedge configuration matching and opposite to the tapered wedge second portion of the inner element, and an outer surface, the outer surface having a circumferential groove formed therein. And a generally tubular nut element having a through extending internal bore with a first portion of the bore having internal screw threading corresponding to and mating with the external screw threaded first portion of the inner element, and having a second portion comprising a flange cooperating with the groove in the outer element. According to the present invention, the mounting device further comprises: Means for holding the inner and outer elements together so that the matching and opposite tapered wedge portions thereof may move with respect to each other to allow attachment to and release from a shaft extending through the internal bores of all of the elements, but not allowing relative movement between the inner and outer elements so that they detach from each other and the segments of the outer element become disassembled.
The holding means of the invention preferably comprises a through extending radial opening in each of the segments of the outer element, and a circumferential groove in the outer surface of the inner element with first and second axially spaced radially extending walls. A collar (e.g. of aluminum) surrounds the outer element at the radial openings, and the collar preferably has its own radial openings aligned with the radial openings in the outer element. A plurality of fasteners extend through the collar radial openings and the outer element radial openings into the inner element circumferential groove and are engageable with the radially extending walls of the inner element circumferential groove to provide a stop for the relative axial movement of the inner and outer elements with respect to each other.
The collar radial openings may be screw threaded, and the fasteners comprise screw threaded fasteners for cooperating with the screw threaded radial openings of the collar. The radially extending walls of the inner element circumferential groove may be spaced apart a distance of about 0.5-0.7 inches (e.g. 0.61 inches) to allow relative axial movement of the inner and outer elements with respect to each other a distance equal to the spacing minus the width (e.g. diameter) of one of the fasteners (e.g. about 0.2 inches).
Also optionally there is provided a radially extending flange rigidly and permanently connected to the nut element, and having a plurality of through extending openings therein parallel to the internal bore. A plurality of fasteners pass through these openings in the flange for connecting the flange to a disk which incorporates a handle that facilitates greater leverage and torque to be applied to the nut for securing the mounting element to the machine element and the shaft. The external flange (if provided) and the nut may be of steel (and welded together), and the collar may be of aluminum and have a recess for seating the external flange therein.
The collar or machine element may have a hub which is where the plurality of screws are secured. Each of the screws go through the outer element pieces to the groove of the inner element. The collar also may have a first portion on which the radial extending openings are provided, having a first relatively small diameter, and a second portion adjacent the machine element and having a second diameter approximately equal to the diameter of the machine element, and significantly greater than the first diameter. An adaptor element may also be provided surrounding the collar and releasably connected to the collar by at least one radially extending fastener. The number of segments of the outer element may comprise three, and the radially extending openings in the outer element are preferably circumferentially elongated, so as to facilitate positioning of the fasteners within them.
It is a primary object of the present invention to provide enhanced functionality of an advantageous prior art mounting device for mounting a machine element to a rotary shaft, particularly in environments where the device must be frequently assembled and disassembled to the shaft, without adversely affecting operation of the device. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.